One of the more common scams in the auto industry is the dirty air filter scam.
The way the scam works is the mechanic will show the customer a black and dusty air filter. But the filter may not actually be yours. Some untrustworthy car shops keep a dirty filter on hand to trick customers into buying something they don't need.
Some air filters only need replaced every $15,000 to $20,000 miles. Find out when yours needs replaced.